Transmission of V. cholerae from infected fish to naive fish. Four or five “donor” fish were exposed to V. cholerae in water for 3 h and then washed twice and placed in a fresh beaker with naive “recipient” fish for 24 h. Data shown were collected from plating serial dilutions of intestinal homogenates 24 h after exposure of the naive fish to the infected fish. Strains used: classical, O395; El Tor, E7946.

Effect of toxT deletion on zebrafish colonization by El Tor V. cholerae. Each dot represents the data from one fish, and the horizontal bar indicates the mean bacterial load per fish. Total colonization per intestine was calculated after plating serial dilutions of intestinal homogenate 24 h postinfection. Strains used were the El Tor strain E7946 and a derivative of E7946 having a complete in-frame toxT deletion.